An alternator is used within a vehicle to selectively provide electrical current to various components and/or assemblies which are contained within the vehicle. Particularly, the alternator is typically mounted upon the vehicle engine assembly (e.g., the intake manifold portion of the engine) by the use of a mounting bracket and emits a time-varying magnetic field which allows the desired electrical current to be produced.
The emitted magnetic field creates a time-varying force within and/or upon the alternator. The structure of the alternator and/or its mounting brackets respond to this force by vibrating in various modes (e.g., a lateral vibration mode or a mode in which the vibration is substantially parallel to an axis which longitudinally extends along the mounting bracket), which causes the alternator assembly to produce a relatively unpleasant and undesirable noise which is similar to a "whine" and which is typically and undesirably communicated into the vehicle passenger compartment, thereby annoying and/or alarming the vehicle occupants.
The amplitude of the lateral vibration varies in accordance with the operating speed of the alternator. Importantly, the lateral vibration amplitude typically attains a relatively large and significant value at an alternator operating speed which corresponds to about 1550 revolutions per minute and which typically occurs as the engine enters or occupies an idle state. Since the vehicle is substantially stationary during such an engine idle state, thereby reducing and/or eliminating the need for the driver to be focused upon the task of driving or maneuvering the vehicle and reducing the noise which is generated by the engine, tires, and airflow, the undesired "whine" is readily noticed or perceived by the driver and/or passengers of the vehicle.
There is therefore a need for a new and improved alternator mounting bracket which substantially reduces the amplitude or amount of such undesired noise as the engine enters an idle state.